(a) Field of the Invention
The present invention relates to a system and method for endpoint discovery based on the Data Distribution Service.
(b) Description of the Related Art
The Data Distribution Service (DDS) is a communication middleware standard that was defined by the OMG (Object Management Group) and that offers communication flexibility, extensibility, and interoperability required for real-time distributed communication environments using a real-time publish-subscribe method of data-centric.
The DDS provides various types of QoS (Quality-of-Service) and constructs various publish-subscribe communication environments using combination of QoS parameters. Also, DDS provides a standard discovery method for participants and endpoints in a data distribution service network to offer compatibility between heterogeneous devices and ensure free participation in or withdrawal from the network.
The standard discovery method for DDS is split into two phases: the Participant Discovery Protocol (PDP) for acquiring information about nodes participating in a network; and the Endpoint Discovery Protocol (EDP) for acquiring publisher and subscriber information that is used for communication based on the acquired node information. The Participant Discovery Protocol (PDP) is transmitted to the network via multicasting or broadcasting, so it is not possible to physically discover participants in areas beyond multicast coverage. Due to this, information about participants in areas beyond multicast coverage is statically registered and used. However, the participant information needs to be modified each time there is a change in the status of participants.
Moreover, nodes within the transmission range of the Participant Discovery Protocol (PDP) deliver information about all publishers and subscribers in a full-mesh topology through the Endpoint Discovery Protocol (EDP). In the full-mesh topology, however, information about endpoints which do not need to be interconnected is delivered to and stored in all nodes. This increases memory usage and creates unnecessary traffic during endpoint discovery.
To solve these problems, there has been research into a variety of participant and endpoint discovery methods, including AN, Kyoungho, et al. “Content-based Filtering Discovery Protocol (CFDP): scalable and efficient OMG DDS discovery protocol”, Proceedings of the 8th ACM International Conference on Distributed Event-Based Systems. ACM, 2014, p. 130-141 (hereinafter, ‘Conventional Art 1’), Sanchez-Monedero, Javier, et al. “Bloom filter-based discovery protocol for DDS middleware”, Journal of Parallel and Distributed Computing, 2011, p. 1305-1317 (hereinafter, ‘Conventional Art 2’), Kwon, Ki-Jung; You, Yong-Duck; Choi, Hoon. “A scalable and effective DDS participant discovery mechanism”, Journal of the Korea Institute of Information and Communication Engineering, 2009, p. 1344-1356 (hereinafter, ‘Conventional Art 3’). According to Conventional Art 1 and Conventional Art 2, problems occurring during the transfer of the Endpoint Discovery Protocol (EDP) can be solved, whereas problems occurring during the transfer of the Participant Discovery Protocol (PDP) are hard to solve. Moreover, according to Conventional Art 3, all the problems occurring during the transfer of the Participant Discovery Protocol (PDP) and Endpoint Discovery Protocol (EDP) can be solved. However, the transmission of non-standard protocols may lead to some difficulties in providing interoperability.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.